A US air marshal has been arrested in Nashville after taking photos up women passengers' skirts and dresses as they boarded a plane, according to the Transportation Security Administration this week.

The incident took place on a Southwest Airlines aircraft, and saw Adam Bartsch, a Baltimore-based air marshal, arrested by Nashville International Airport police.

The marshal was caught after someone caught him taking the invasive shots, confiscated his cell phone and told the flight attendant what he had seen, according to the criminal affidavit in the case.

The suspect has been charged with disorderly conduct, and according to the affidavit, he has "admitted to taking pictures underneath females' dresses and or skirts."

A spokesman for Southwest Airlines also stepped forward to publicly confirm that the airline's crew had "removed a passenger" from flight 3132.

The flight was scheduled to travel to Tampa, but was delayed after the incident and arrest.

Michael Pascarella, a Federal Air Marshal Service spokesman, said: "The agency immediately removed this individual from his current duties and is in the process of suspending or terminating his employment. TSA continues to assist with the investigation."